Spectral gap in the group of affine transformations over prime fields
arXiv:1409.3564 · doi:10.5802/afst.1518
Abstract
We study random walks on the semi-direct product of F_p^d and SL_d(F_p). We estimate the spectral gap in terms of the spectral gap of the projection to the linear part SL_d(F_p). This problem is motivated by an analogue in the isometry group of Euclidean space, which have application to smoothness of self-similar measures.
25 pages, final version, results are unchanged, modified the argument relating L^2 and L^4 estimates using the Riesz-Thorin theorem, rest of the arguments are unchanged